JP2023184703A - inkjet recording device - Google Patents

Abstract

To provide an inkjet recording device which can facilitate cleaning of a print head and easily recover a solvent (a cleaning fluid) used for the cleaning.SOLUTION: An inkjet recording device includes: a print head which receives supply of an ink to perform printing; and a body which includes an ink container for storing an ink and a solvent container for storing a solvent and supplies the ink in the ink container to the print head. The inkjet recording device includes a washing tank, a cleaning nozzle, and a recovery container. The print head is set within the washing tank, the solvent is jetted from the cleaning nozzle to wash the print head, and the solvent after washing is recovered by the recovery container.SELECTED DRAWING: Figure 4

Description

The present invention relates to an inkjet recording apparatus that continuously ejects ink from nozzles to print on a printing medium.

As a technique related to nozzle cleaning in this technical field, the technique described in Japanese Patent Laid-Open No. 2002-103636 (Patent Document 1) is known. Patent Document 1 states, ``In the print head, a cleaning jet that is shifted to the side of the nozzle and fixed is installed downstream of the ink nozzle to be cleaned.When the ink jet stops, this cleaning jet causes a predetermined amount of solvent is injected, which hits the nozzle at a predetermined angle. In this way, the front side of the droplet generator is cleaned and the ink residue is ejected towards the opposite side of the housing. Dry compressed air is then blown through the cleaning jet and toward the ink nozzle to dry the front of the nozzle and deposit ink residue on the side of the housing.'' There is.

Further, as another technique related to nozzle cleaning, the technique described in Japanese Patent Application Laid-open No. 2015-136934 (Patent Document 2) is known. Patent Document 2 states, ``In order to clean the nozzles of the head, a cleaning nozzle, that is, an ASC nozzle is provided.This ASC nozzle is used to spray cleaning liquid (solvent) from the ASC nozzle to clean the nozzle discharge port Specifically, the ASC nozzle (cleaning nozzle) is arranged inside the head facing the nozzle discharge port.This ASC nozzle (cleaning nozzle) is connected to the solvent line and It communicates with the solvent tank. When cleaning the nozzle, the air valve, which is an on-off valve, is opened and the solvent supplied from the solvent tank is injected from the ASC nozzle."

Japanese Patent Application Publication No. 2002-103636 Japanese Patent Application Publication No. 2015-136934

In the technique disclosed in Patent Document 1, when the print head is washed (cleaned), the ink residue adhering to the nozzles inside the print head ends up adhering to a part other than the nozzles (the side of the housing of the print head). Therefore, it is necessary for a separate worker to manually clean the affected area with a solvent, but this work is troublesome. Further, Patent Document 1 does not describe how to treat the solvent after cleaning.

Furthermore, the technology disclosed in Patent Document 2 sprays a solvent (cleaning liquid) from a cleaning nozzle (ASC nozzle) provided in the print head to clean the nozzle discharge port. Manual work is required to remove ink residue from the head. Further, Patent Document 2 also does not describe how to process the solvent (cleaning liquid) after cleaning the print head.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an inkjet recording device and a method for controlling the inkjet recording device that can clean the printhead and easily recover the solvent (cleaning liquid) used for cleaning the printhead. be.

In order to achieve the above-mentioned object, the present invention includes, for example, a print head that receives ink supply and performs printing, an ink container for storing ink, and a solvent container for storing solvent. a main body that supplies the ink in the ink container to the print head, and the print head has a nozzle that ejects the ink as ink particles, and a main body that supplies the ink in the ink container to the print head; An inkjet recording device comprising: a charging electrode that is charged in accordance with printing content; a deflection electrode that changes the flight direction of the charged ink particles; and a gutter that collects the ink particles that do not contribute to the printing. a cleaning tank for setting the print head; a cleaning nozzle for spraying the solvent toward the print head set in the cleaning tank to clean the print head; and a cleaning nozzle provided at the bottom of the cleaning tank for cleaning. The present invention is an inkjet recording apparatus that is provided with a head cleaning unit including a recovery container for later recovering the solvent, and a drive unit that supplies the solvent to the cleaning nozzle.

Another example of the present invention includes a print head that receives ink and performs printing, an ink container for accommodating ink, and a solvent container for accommodating solvent; a main body for supplying the ink to the print head, the print head being set inside a cleaning tank equipped with a cleaning nozzle that ejects the solvent, and then, In this method of controlling an inkjet recording apparatus, the solvent is ejected from the cleaning nozzle to clean the print head, and the solvent after cleaning is collected by a collection container provided at the bottom of the cleaning tank.

According to the present invention, there is provided an inkjet recording device and a method for controlling the inkjet recording device, in which the print head can be easily cleaned and the solvent (cleaning liquid) used for cleaning the print head can be easily recovered. be able to.

FIG. 1 is a perspective view showing how the inkjet recording apparatus is used in Example 1 of the present invention. FIG. 2 is a perspective view showing a print head set in a cleaning unit in Example 1. FIG. FIG. 3 is a perspective view showing a state in which the head cleaning unit is fixed to the main body in Example 1. 1 is a diagram showing a path configuration of an inkjet recording apparatus in Example 1. FIG. FIG. 3 is a diagram showing a path configuration of the inkjet recording apparatus in a state in which a head cleaning unit is removed in Example 1. FIG. FIG. 3 is a diagram showing the path configuration of the head cleaning unit in a state where it is removed from the main body of the inkjet recording apparatus in Example 1. FIG. 3 is a fluid path diagram showing, in bold lines, the flow of liquid during head cleaning processing in Example 1. FIG. FIG. 3 is a fluid path diagram showing the flow of air during the head drying process in Example 1 using thick lines. FIG. 2 is a fluid path diagram showing the flow of ink and solvent using thick lines when the ink and solvent replenishment operations are performed in Example 1. FIG. FIG. 3 is a fluid path diagram showing the flow of ink using thick lines when ink circulation processing is performed in Example 1. FIG. 1 is a configuration diagram of a print head in Example 1. FIG. 3 is a configuration diagram of a head cleaning unit in Example 1. FIG. FIG. 3 is a cross-sectional view of the head cleaning unit in a state in which a print head is set in the head cleaning unit in Example 1. 14 is an enlarged view of the vicinity of the print head in FIG. 13. FIG. FIG. 3 is a cross-sectional view of the head cleaning unit showing the flow of liquid inside the head cleaning unit using thick lines when head cleaning processing is performed in Example 1; In Example 1, liquid level detection of the collection container in each state is shown. FIG. 3 is a cross-sectional view of the head cleaning unit when draining the liquid from the collection container is being performed in Example 1. FIG. 2 is an external perspective view of an inkjet recording apparatus in Example 2 of the present invention. 7 is a perspective view showing a state in which a print head is set in a cleaning unit in an inkjet recording apparatus in Example 2. FIG. 3 is a diagram showing a path configuration of an inkjet recording apparatus in Example 2. FIG.

Hereinafter, specific embodiments of the present invention will be described using the drawings. Note that the present invention is not limited to the examples described below. In addition, in each of the following figures, the same numbers (symbols) are given to the same equipment, and the description of the equipment that has already been described may be omitted.

≪Example 1≫
<Usage condition>
First, the usage state of the inkjet recording apparatus 600 in Example 1 of the present invention will be explained using FIGS. 1 to 3. FIG. 1 is a perspective view showing how the inkjet recording device 600 in this embodiment is used, and FIG. 2 shows the inkjet recording device 600 in this embodiment in which the print head 2 is attached to the head cleaning unit 4. FIG. FIG. 3 is a perspective view showing a state in which the head cleaning unit 4 is fixed to the main body 1 in the inkjet recording apparatus 600.

First, as shown in FIG. 1, an inkjet recording apparatus 600 according to the present embodiment includes a main body 1, a print head 2 connected to the main body 1 by a conduit (for the print head) 5, and a head cleaning unit for the main body 1. and a head cleaning unit 4 connected by a conduit 6.

The inkjet recording device 600 is installed, for example, on a production line in a factory where foods, drinks, etc. are produced, and the main body 1 is installed in a location where the space necessary for regular maintenance work can be secured. The print head 2 is fixed to a print head fixing fitting 13 installed near the belt conveyor 11, and prints on print objects 12A to 12B that are fed in the direction of arrow XX on a production line such as the belt conveyor 11. are located close together to ensure that Further, a protective cover 17 is attached to the print head 2 for the purpose of protecting components inside the print head 2.

In such an inkjet recording device 600, a control unit 10 (the specific configuration is not shown) provided inside the main body 1 charges ink particles 68B ejected from a nozzle 21 assembled to the print head 2. Controls the amount and timing of charging. That is, the control unit 10 causes the charged and deflected ink particles 68B to adhere to the printing object (during printing) 12B while the printing object (before printing) 12A passes near the print head 2 to perform printing. control. The control unit 10 also controls electromagnetic valves, pumps, etc. provided within the main body 1 to control the flow of ink and the flow of solvent. Note that the control unit 10 can use a computer. Specifically, the control unit 10 includes a microprocessing unit (MPU), a memory that stores programs for the operation of the MPU and data and information necessary for the operation, and a control unit that controls the print head and the main body 1 according to instructions from the MPU. It can be configured with a print drive unit that operates the component devices. Here, details of the control unit 10 are omitted.

The head cleaning unit 4 is installed around the print head 2. The head cleaning unit 4 in this embodiment is fixed by combining a fixing jig A (for conveyor) 92 assembled to the belt conveyor 11 with a fixing jig fitting part 93 assembled to the head cleaning unit 4. ing. The head cleaning unit 4 has a print head insertion portion 72A that is an opening for inserting the print head 2 into the head cleaning unit 4.

Furthermore, the head cleaning unit 4 has a start button 63 for starting the cleaning process for the print head 2, a stop button 64 for stopping the cleaning process for the print head 2, and a confirmation message and alarms such as alarms and abnormalities. It also has a display section 65 for the operator to recognize.

The main body 1 has a fixing jig (for the main body) 91 for fixing the head cleaning unit 4, and the head cleaning unit 4 can be removed from the fixing jig (for the conveyor) 92. It is also possible to use it by replacing it with a fixing jig (for main body) 91. In this embodiment, the head cleaning unit 4 is fixed to the belt conveyor 11, but in the inkjet recording apparatus 600 of this embodiment, the head cleaning unit 4 can be freely replaced at a location that is easy for the user to operate. be.

Next, with reference to FIG. 2, a state in which the print head 2 is set in the head cleaning unit 4 in the inkjet recording apparatus 600 will be described. The print head 2 is inserted and set into the print head insertion portion 72A of the head cleaning unit 4 from the tip of the print head 2. In the inkjet recording apparatus 600 of this embodiment, by setting the print head 2 in the head cleaning unit 4 in this way, the print head 2 is cleaned by the solvent (cleaning liquid) supplied from the main body 1 side through the conduit 6. can do.

The length of the conduit (for head cleaning unit) 6 that connects the main body 1 and the head cleaning unit 4 is the same as the length of the conduit (for print head) 5 that connects the main body 1 and the print head 2 of the inkjet recording device. , it is preferable to make it longer. This is to ensure flexibility in the arrangement of the head cleaning unit 4.

Next, with reference to FIG. 3, a state in which the head cleaning unit 4 is fixed to the main body 1 in the inkjet recording apparatus 600 will be described. The head cleaning unit 4 can be fixed to the main body 1 by combining the fixing jig 91 assembled to the main body 1 with the fixing jig engagement part 93. By making the head cleaning unit 4 fixable to the main body 1, the head cleaning unit 4 can be installed even when there is no space to attach the head cleaning unit 4 to the belt conveyor 11 or the like.

<Route configuration>
Next, the path configuration of the inkjet recording apparatus 600 in this embodiment will be explained using FIG. 4. FIG. 4 is a diagram showing the overall path configuration of the inkjet recording apparatus 600 in this embodiment.

First, the ink supply paths (paths 801 to 803) of the inkjet recording apparatus 600 in this embodiment will be explained. In FIG. 4, the main body 1 is equipped with an ink container 31 that holds circulating ink 68A. The ink container 31 is equipped with a liquid level sensor 31A that detects whether the liquid in the ink container 31 has reached a reference liquid level that is an appropriate amount to be retained inside.

The ink container 31 is connected to a path (for supply) 801 at the part immersed in the ink 68A, and a solenoid valve (for supply) 49 is installed in the middle of the path 801 to open and close the path. . Further, the path 801 is connected via a confluence path 901 to a pump (for supply) 34 installed in the path 802 and used for sucking and pumping the ink 68A. The output side of the pump (for supply) 34 is connected to a filter (for supply) 39 that removes foreign matter mixed in the ink 68A.

The filter (for supply) 39 is connected to a pressure regulating valve 46 that adjusts the ink 68A pumped from the pump (for supply) 34 to an appropriate pressure for printing, and the pressure regulating valve 46 is supplied to the nozzle 21. It is connected to a pressure sensor 47 that measures the pressure of the ink 68A. A path 802 in which the pressure sensor 47 is disposed passes through the conduit (for print head) 5 and connects to a switching valve 26 provided in the print head 2 for controlling whether or not to supply ink 68A to the nozzle 21. It is connected to the.

The switching valve 26 is connected via a path 803 to a nozzle 21 having an ejection port 21A that ejects ink 68A. The switching valve 26 is a three-way solenoid valve, and an ink supply path 802 and a nozzle cleaning path 812 are connected to the switching valve 26, and the ink 68A and solvent 69A are supplied to the nozzle 21. Can be switched. In the straight direction of the ejection opening 21A of the nozzle 21, there are a charging electrode 23 for adding a predetermined amount of charge to the ink particles 68B, a deflection electrode 24 for deflecting the ink particles 68B used for printing, and a charging electrode 24 for deflecting the ink particles 68B used for printing. A gutter 25 is disposed to catch ink particles 68B that fly straight without being charged or deflected.

Next, the ink recovery path 804 of the inkjet recording apparatus 600 in this embodiment will be explained. In FIG. 4, the gutter 25 is connected to a path 804, and a charge sensor 48 is disposed in the path 804 to detect whether the ink particles 68B to which an electric charge has been added by the charging electrode 23 are collected. ing. The path 804 passes through the conduit (for print head) 5 and is connected to a filter (for collection) 40 disposed in the main body 1 for removing foreign matter mixed in the ink. (For recovery) 40 is connected to a solenoid valve (for recovery) 50 that opens and closes the path.

The electromagnetic valve (for collection) 50 is connected to a pump (for collection) 35 that sucks ink particles 68B captured by the gutter 25, and the pump (for collection) 35 is connected to the ink container 31. By opening the electromagnetic valve 50 and driving the pump 35, the ink particles 68B captured by the gutter 25 are collected into the ink container 31. Further, the ink container 31 is connected to a path 805 in an upper space that does not come into contact with the ink 68A, and the path 805 is configured to communicate with the outside of the main body 1.

Next, the ink circulation path (paths 806 to 807) of the inkjet recording apparatus 600 in this embodiment will be explained. The nozzle 21 provided in the print head 2 is connected to a path 806 passing through the conduit (for the print head) 5 in addition to a path 803 for supplying ink. In this path 806, a solenoid valve (for circulation) 51, which is provided in the main body 1 and opens and closes the flow path, is arranged.

The electromagnetic valve (for circulation) 51 is connected to a path 807 via a confluence path 902, and a pump (for circulation) 36 that sucks ink from the nozzle 21 is disposed in the path 807. A pump (for circulation) 36 is connected to the ink container 31.

Next, the viscosity measurement paths (paths 808 and 807) of the inkjet recording apparatus 600 in this embodiment will be explained. In FIG. 4, the ink container 31 is connected to the path 808 at the portion immersed in the ink 68A. The path 808 is connected to the viscosity measuring device 45 via the path 801 in order to determine the viscosity of the ink 68A in the ink container 31. The viscosity measuring device 45 is connected to a solenoid valve (for viscosity measurement) 52 that opens and closes the path. The electromagnetic valve (for viscosity measurement) 52 is connected to a pump (for circulation) 36 disposed in a path 807 via a confluence path 902 . Thereby, the ink 68A in the ink container 31 is circulated through the viscosity measurement path, and the viscosity of the ink 68A can be measured. The age measured in this way is input to the illustrated control unit 10 and used to control the viscosity of the ink 68A in the ink container 31.

Next, the solvent supply route (routes 809 to 810) of the inkjet recording apparatus 600 in this embodiment will be explained. In FIG. 4, the main body 1 is equipped with a solvent container 33 that holds a solvent 69A used for replenishing the ink container 31 with solvent, cleaning the nozzle, or cleaning the head. The portion of the solvent container 33 immersed in the solvent 69A is connected to a path 809, and a pump (for solvent) 37 used for sucking and pumping the solvent is disposed in the path 809. The pump (for solvent) 37 is connected to a branch path 903 in order to change the supply destination of the solvent 69A depending on the purpose. The branch path 903 is connected to the solenoid valve (for solvent replenishment) 53 in order to open and close the flow path arranged in the path 810 in the solvent replenishment path, and the solenoid valve (for solvent replenishment) 53 is connected to the ink container 31 . The configuration is connected to

Next, the ink replenishment path 811 of the inkjet recording apparatus 600 in this embodiment will be explained. In FIG. 4, the main body 1 is equipped with an auxiliary ink container 32 that holds replenishment ink 68C. The auxiliary ink container 32 is connected to the path 811 at the portion immersed in the ink 68C. The path 811 is connected to a solenoid valve (for ink replenishment) 54 that opens and closes the path, and the solenoid valve (for ink replenishment) 54 is installed in the path 802 via the merging path 901 to suck ink 68C. , is connected to a pump (for supply) 34 used for pressure feeding. The ink 68C in the auxiliary ink container 32 is replenished into the ink container 31 via the nozzle 21, the gutter 25, the path 804, the electromagnetic valve 50, and the pump 35.

Next, the nozzle cleaning paths (paths 809 and 812) of the inkjet recording apparatus 600 in this embodiment will be explained. In FIG. 4, the pump (for solvent) 37 arranged in the path 809 is connected to the path 812 via the branch path 903. The path 812 is connected to a solenoid valve (for nozzle cleaning) 55 for opening and closing the flow path. The solenoid valve (for nozzle cleaning) 55 is connected to a filter (for nozzle cleaning) 41 for removing foreign matter mixed in the solvent 69A. A filter (for nozzle cleaning) 41 is provided in the print head 2 via a path 812 passing through the conduit (for print head) 5, and is used to control whether or not to send the cleaning solvent 69A to the nozzle 21. It is configured to be connected to a switching valve 26.

Next, the head cleaning paths (path 809, paths 821 to 822) of the inkjet recording apparatus 600 in this embodiment will be explained. In FIG. 4, the pump (for solvent) 37 is connected to a path 821 via a branch path 903, and the path 821 is connected to a connection part (head It is connected to the path 822 via a joint (for head cleaning) 59A and a joint (for head cleaning) 60A. A solenoid valve (for nozzle cleaning) 56 for opening and closing the flow path is disposed in the path 822, and the solenoid valve (for nozzle cleaning) 56 is a filter for removing foreign matter mixed in the solvent 69A. (for head cleaning) 42.

A filter (for head cleaning) 42 is provided in the head cleaning unit 4 via a path 822 passing through the conduit (for head cleaning unit) 6, and removes foreign substances that may initially be mixed into the path 822. It is connected to a filter (for cleaning nozzle) 43 for cleaning. The output side of the filter (for cleaning nozzle) 43 is connected to a cleaning nozzle 74 provided inside the cleaning tank 71 of the head cleaning unit 4 . Here, the space inside the cleaning tank 71 is configured to communicate with a collection container 73 installed at the bottom.

Next, the solvent reuse paths (paths 823 to 824 and path 807) of the inkjet recording apparatus 600 in this embodiment will be explained. In FIG. 4, the head cleaning unit 4 is equipped with a recovery container 73 that holds the recovered solvent 69B after head cleaning, which flows in under its own weight after being used for head cleaning. A filter (for the collection container) 77 is attached to the collection container 73 to prevent foreign matter mixed in during head cleaning from flowing into the path 823. The recovery container 73 is connected to the path 823 at the portion immersed in the recovery solvent 69B. The path 823 passes through the conduit (for the head cleaning unit) 6 and is connected to the filter (solvent reuse) 44 in the drive unit 3 inside the main body 1 . This filter 44 is provided to prevent fine foreign matter contained in the recovered solvent 69B from being mixed into the ink 68A.

Further, the output side of the filter (solvent reuse) 44 is connected through a path 823 to a solenoid valve (solvent reuse) 57 for opening and closing the flow path. The path 823 in which the electromagnetic valve (solvent reuse) 57 is disposed is connected to the path 824 via the connection part (solvent reuse) 59B and the connection part (solvent reuse) 60B for relaying between the main body 1 and the drive unit 3. It is connected to the. The path 824 is connected to the pump (for circulation) 36 arranged in the path 807 via the confluence path 902. Thereby, the recovery solvent 69B held in the recovery container 73 can be supplied to the ink container 31 in the main body 1 via the drive unit 3. This replenishment makes it possible to adjust the ink concentration (viscosity) and can be reused for viscosity adjustment. That is, when the viscosity detected by the viscosity measuring device 45 exceeds a predetermined value, the control unit 10 transfers the solvent 69B used for cleaning the inside of the collection container 73 to the path 823, the filter 44, the electromagnetic valve 57, the connection part 60B, The ink is supplied to the ink container 31 via the path 824 branch 902, the path 807, and the pump 36.

Next, the head drying air path 825 of the inkjet recording apparatus 600 in this embodiment will be explained. In FIG. 4, the drive unit 3 housed in the main body 1 is equipped with a pump (for supplying dry air) 38 used for suctioning and pumping air. forms an air suction port communicating with the inside of the main body 1. The pump (for supplying dry air) 38 is connected to an air nozzle 75 provided inside the cleaning tank 71 of the head cleaning unit 4 via a path 825 passing through the conduit (for the head cleaning unit) 6 .

<Head cleaning unit built-in structure>
The configuration of incorporating the head cleaning unit 4 into the inkjet recording apparatus 600 in this embodiment will be explained using FIGS. 4 to 6. FIG. 4 is a path configuration diagram showing a state in which the head cleaning unit 4 is installed in the inkjet recording apparatus 600 in this embodiment. FIG. 5 is a path configuration diagram showing a state in which the head cleaning unit 4 is not incorporated in the inkjet recording apparatus 600 in this embodiment. FIG. 6 is a path configuration diagram of the head cleaning unit 4 and the drive unit 3.

In FIG. 5, the main body 1 of the inkjet recording apparatus 600 is in a state with the head cleaning unit 4 and drive unit 3 removed. In the path 821 connected to the cleaning nozzle 74 of the head cleaning unit 4, a sealing plug 61A is attached to the connecting portion (for head cleaning) 59A to close the flow path. Further, in the path 824 connected to the collection container 73 of the head cleaning unit 4, a sealing plug 61B is attached to the connection part (solvent reuse) 59B to close the flow path. Furthermore, the main body 1 has a storage area 58 in which the drive unit 3 is placed.

Next, in FIG. 6, the head cleaning unit 4 is shown removed from the main body 1 of the inkjet recording apparatus 600. The head cleaning unit 4 is connected to the drive unit 3 by a conduit (for the head cleaning unit) 6. The drive unit 3 incorporates a pump (for dry air supply) 38, a solenoid valve (for head cleaning) 56, a solenoid valve (solvent reuse) 57, a filter (for head cleaning) 42, and a filter (solvent reuse) 44. It consists of

In this way, in the inkjet recording apparatus 600 of this embodiment, the main body 1 and the head cleaning unit 4 can be separated. This makes it easy to carry the head cleaning unit 4, the drive unit 3, and the conduit 6 that connects these drive units 3 and 4 as one head cleaning device. When cleaning the print head 2, this head cleaning device is attached to the main body 1 and used.

<Operation and liquid flow>
Next, the operation of the inkjet recording apparatus 600 in this embodiment will be explained.

FIG. 7 is a fluid path diagram showing, in bold lines, the flow of solvent and the flow of air when the head cleaning process is performed in the inkjet recording apparatus 600 according to the first embodiment.
In FIG. 7, the inkjet recording apparatus 600 is in a state where the print head 2 is set (inserted) in the head cleaning unit 4 for cleaning. In the head cleaning path (path 809, paths 821 to 822), the solenoid valve (for head cleaning) 56 is energized to open the flow path, and the pump (for solvent) 37 is operated, so that the thick line indicated by arrow A As shown, solvent can be supplied to the head cleaning unit 4. That is, the solvent 69A contained in the solvent container 33 of the main body 1 can be supplied to the cleaning nozzle 74 assembled in the cleaning tank 71 of the head cleaning unit 4.

The cleaning nozzle 74 sprays this solvent 69A toward the print head to clean the print head. Specifically, part of the solvent 69A supplied to the cleaning nozzle 74 is ejected toward the nozzle 21 surrounded by the protective cover 17 of the print head 2, as shown by the thick line of arrow B, and the other part is ejected toward the nozzle 21 surrounded by the protective cover 17 of the print head 2. A portion is ejected toward the protective cover 17 on the outside of the print head 2 as shown by the bold line of arrow C. As shown by the thick line of arrow B, the solvent 69A discharged from the cleaning nozzle 74 cleans components such as the nozzle 21 assembled inside the print head 2, the charging electrode 23, the deflection electrode 24, and the gutter 25. , as shown by the bold line of arrow E, it hangs downward due to gravity. The solvent 69A that has dripped to the lower part of the cleaning tank 71 flows toward the collection container 73 as shown by the bold line of arrow F, and is stored inside the collection container 73 as a collection solvent 69B.

In the ink circulation path (paths 806 to 807), the solenoid valve (for circulation) 51 is energized to open the flow path and the pump (for circulation) 36 is operated, as shown by the thick line of arrow G. A part of the solvent 69A that hit the nozzle 21 is sucked out from the nozzle 21A and collected into the ink container 31 of the main body 1. In this way, in the head cleaning process, the inside of the nozzle 21 and the ink circulation paths 806 to 807 can also be cleaned with the solvent 69A.

Furthermore, in the ink recovery path 804, the solenoid valve (for recovery) 50 is energized to open the flow path, and the pump (for recovery) 35 is operated, so that the gutter is removed as shown by the thick line of arrow H. A portion of the solvent 69A that has hit the ink cartridge 25 is sucked from the gutter 25 and collected into the ink container 31 of the main body 1. In this way, in the head cleaning process, the inside of the gutter 25 and the ink recovery path 804 can also be cleaned with the solvent 69A.

Next, FIG. 8 is a fluid path diagram showing the flow of air when the head drying process is performed in the inkjet recording apparatus 600 according to the present embodiment using thick lines. In FIG. 8, the inkjet recording apparatus 600 has the print head 2 set in the head cleaning unit 4, and after the head cleaning process is completed, the head drying process is performed. In the head cleaning path 825, compressed air is pumped into the cleaning tank 71 of the head cleaning unit 4 by operating the pump (for dry air supply) 38 installed in the main body 1, as shown by the bold line of arrow J. The air is supplied to the assembled air nozzle 75.

A portion of the air supplied to the air nozzle 75 is ejected toward the charged electrode 23 surrounded by the protective cover 17 of the print head 2 as shown by the bold line of arrow K, and the other portion is ejected toward the charging electrode 23 surrounded by the protective cover 17 of the print head 2 as shown by the thick line of arrow K. The liquid is ejected toward the outer protective cover 17 of the print head 2 as shown by the thick line. The air discharged from the air nozzle 75, as shown by the thick line of arrow K, dries the components assembled inside the print head 2, such as the nozzle 21, the charging electrode 23, the deflection electrode 24, and the gutter 25.

In the ink recovery path 804, the electromagnetic valve (for recovery) 50 is energized to open the flow path, and the pump (for recovery) 35 is operated, so that a portion of the air is removed as shown by the thick line of arrow M. is sucked from the gutter 25, and is sucked and pressure-fed into the ink container 31 of the main body 1. In addition, in the ink circulation path (paths 806 to 807), the solenoid valve (for circulation) 51 is energized to open the flow path, and the pump (for circulation) 36 is operated, as indicated by the thick line of arrow N. A part of the air is sucked from the nozzle 21, and is sucked and pressure-fed into the ink container 31 of the main body 1. The air that has flowed into the ink container 31 is then exhausted to the outside of the main body 1 through the exhaust path 805 as indicated by the thick line of arrow P. In this way, by suctioning air from the gutter 25 and nozzle 21 during the head drying process, the amount of solvent gas discharged around the head cleaning unit 4 can be reduced. If the flow rate of the air sucked from inside the cleaning tank 71 by the gutter 25 and nozzle 21 is higher than the flow rate of the air supplied from the air nozzle 75 into the cleaning tank 71, the solvent gas will flow around the head cleaning unit 4. Diffusion can be minimized.

Next, FIG. 9 shows the ink when the circulation control of the ink 68A, the replenishment control of the ink 68C, and the replenishment control of the solvents 69A and 69B are performed during operation in the inkjet recording apparatus 600 in this embodiment. FIG. 3 is a fluid path diagram showing the flow of solvent and air with thick lines. In FIG. 9, the inkjet recording apparatus 600 shows that the print head 2 has been removed from the head cleaning unit 4 and is ready for printing. In the ink supply paths 801 to 803, the solenoid valve (for supply) 49 is energized to open the flow path, and the pump (for supply) 34 is operated, as shown by the bold lines of arrows Q and R. The ink 68A contained in the ink container 31 of the main body 1 is supplied to the nozzle 21 of the print head 2, and is ejected from the nozzle 21 as ink particles 68B.

In the ink recovery path 804, the electromagnetic valve (for recovery) 50 is energized to open the flow path, and the pump (for recovery) 35 is operated, so that the ink particles 68B and Air around the print head 2 is sucked through the gutter 25, and is sucked and forced into the ink container 31 of the main body 1. In the ink recovery path 804, the ink 68A and air flow in a gas-liquid mixture, so the solvent component of the ink 68A dissolves in the air, and the air becomes a solvent gas and flows into the ink container 31. The ink 68B that has flowed into the ink container 31 is stored at the bottom, and the air that has become a solvent gas is discharged to the outside of the main body 1 as a solvent gas, as shown by arrow T.

In the inkjet recording apparatus 600, the solvent component in the ink 68A is discharged outside the machine as a solvent gas, so as the operating time becomes longer, the ratio of the solvent component in the ink 68A decreases, and the concentration of the ink 68A decreases. becomes dark. Therefore, in the viscosity measurement paths 808 and 807, the solenoid valve (for viscosity measurement) 52 is energized to open the flow path, and the pump (for circulation) 36 is operated, as shown by arrows V and W. The ink 68A in the ink container 31 is sent to the viscosity measuring device 45, and the concentration of the ink 68A is periodically measured. This measured viscosity is input to the control section 10. As a result, the control unit 10 replenishes the ink 68C in the auxiliary ink container 32 to the ink container 31 when the concentration of the ink 68A is low, and replenishes the ink 68C in the collection container 73 when the concentration of the ink 68A is high. Control is performed to replenish the ink container 31 with the solvent 69B, or to replenish the ink container 31 with the solvent 69 in the solvent container 33.

In the ink replenishment paths (paths 811 and 802), the solenoid valve (for ink replenishment) 54 is energized and opens the flow path, and the solenoid valve (for supply) 49 is de-energized and closes the flow path. By operating the pump (for supply) 34, the ink 68C in the auxiliary ink container 32 is supplied to the nozzle 21 and discharged from the nozzle 21 as ink particles 68B. The ink 68C is then replenished into the ink container 31 via the ink recovery path 804.

In the solvent reuse paths (823 to 824 and 807), when the concentration of the ink 68A is high, the solenoid valve (solvent reuse) 57 is energized to open the flow path and operate the pump (for circulation) 36. As a result, the recovery solvent 69B contained in the recovery container 73 of the head cleaning unit 4 is replenished into the ink container 31 of the main body 1. In the solvent replenishment paths 809 to 810, when it is detected that the concentration of the ink 68A is high and the liquid level of the recovery container 73 is below the minimum liquid amount detection part 76B of the liquid amount sensor 76, , the solenoid valve (for solvent replenishment) 53 is energized to open the flow path, and the pump (for solvent) 37 is operated, so that the solvent 69A contained in the solvent container 33 is replenished into the ink container 31. It has become.

Next, in FIG. 10, the inkjet recording apparatus 600 according to this embodiment is in a state where the print head 2 is set in the head cleaning unit 4, and the flow of ink when the ink circulation process is performed is shown by a thick line. FIG. In the inkjet recording device 600, even if it is not used for a period of about one to two weeks, ink circulation can be performed periodically (about once every two to three days), so that it can be operated the next time it is used. It is possible to reduce troubles at the time of starting. Therefore, in FIG. 10, a description will be given of control when it is desired to automatically circulate the ink 68A periodically.

In the ink supply path (paths 801 to 803), the solenoid valve (for supply) 49 is energized to open the flow path and the pump (for supply) 34 is operated, as shown by the thick line of arrow AA. The ink 68A contained in the ink container 31 of the main body 1 is supplied to the nozzle 21 of the print head 2, and is ejected from the nozzle 21 as ink particles 68B.

In the ink recovery path 804, the electromagnetic valve (for recovery) 50 is energized to open the flow path, and the pump (for recovery) 35 is operated, so that the ink particles 68B and Air around the print head 2 is sucked through the gutter 25, and is sucked and forced into the ink container 31 of the main body 1. The ink 68B that has flowed into the ink container 31 is stored at the bottom, and the air that has become a solvent gas is discharged to the outside of the main body 1 as a solvent gas as shown by arrow T. Then, as shown by arrow DD, the concentration of the ink 68A is periodically measured by the viscosity measuring device 45, and the concentration (viscosity) of the ink 68A is controlled to be within a certain range.

With the ink circulation of this embodiment, even if the ink particles 68B ejected from the nozzle 21 do not enter the gutter 25 due to some trouble, they can be detected by the charge sensor 48; It is also possible to prevent the ink 68B that has come off from staining the surroundings of the inkjet recording apparatus 600. Even if the charge sensor 48 is unable to accurately detect that the ink particles 68B are not in the gutter 25 due to a malfunction, the maximum liquid volume detection section of the liquid volume sensor 76 provided in the collection container 73 The overflow of the ink 68B can be detected at 76A, and the supply of the ink 68A to the nozzle 21 can be stopped.

Further, in the inkjet recording apparatus 600, it is also possible to perform periodic automatic head cleaning control in addition to periodic automatic circulation control of the ink 68A. By doing so, it becomes possible to further prevent troubles during the next use.

<Print head structure>
Next, a specific configuration of the print head 2 of the inkjet recording apparatus 600 according to Example 1 will be described using FIG. 11. FIG. 11 is a partial cross-sectional view showing the configuration of the print head in this embodiment. In FIG. 11, (a) shows a state in which the protective cover door 18 of the print head 2 is closed, and (b) shows a state in which the protective cover door 18 of the print head 2 is open.

In FIG. 11A, the print head 2 includes a head base 16, a conduit (for the print head) 5 connecting the main body 1 and the print head 2, and a print opening through which ink particles 68B used for printing pass. 17A, and includes a protective cover 17 assembled to the head base 16. The head base 16 is assembled with a switching valve 26, a nozzle 21 connected to the switching valve 26 via a tube 803A, a charging electrode 23, a deflection electrode 24, and a gutter 25. Furthermore, a temperature sensor A27 is installed in the print head 2 to detect the ambient temperature and use it for various controls. When the protective cover 17 is assembled, the space surrounded by the head base 16 and the protective cover 17 is protected from impacts during maintenance.

A cleaning opening 17B is formed in the protective cover 17, and the cleaning opening 17B can be opened and closed by a protective cover door 18 assembled to the protective cover 17. The assembly position of the protective cover door 18 is determined by a pin 20 fixed to the protective cover 17, and the assembly position is determined by a pin 20 fixed to the protective cover 17. It is designed to slide in the opposite direction (arrow DO).

The protective cover 17 forms a seat portion 17D, and a door closing spring 19 is assembled to the seat portion 17D in such a manner that a load is applied to the protective cover door 18 in the direction of arrow DC. The door closing spring pushes the back surface of the opening/closing support part 18A formed on the protective cover door 18 in the direction of arrow DC, so that the protective cover door 18 covers the cleaning opening 17B. At this time, the protective cover door 18 comes to rest at a position where the opening lower end 17C formed on the protective cover 17 and the door lower end 18C formed on the protective cover door 18 come into contact.

A magnet A29 is attached to the lower end portion 18C of the door, and a proximity sensor A28 is attached to the protective cover door 18, which detects when the magnet A29 approaches a certain distance or less. When the protective cover door 18 covers the cleaning opening 17B, the proximity sensor A28 is in a non-detection state because the magnet A29 is away. Therefore, it can be determined that the protective cover 17 covers the cleaning opening 17B, and the nozzle 21, charging electrode 23, and deflection electrode 24 are protected.

Next, referring to FIG. 11(b), a state in which the protective cover door 18 of the print head 2 is open will be described. The opening/closing support portion 18A of the protective cover door 18 is pushed in the direction of the arrow DO, and the door closing spring 19 is in a compressed state. Then, it comes to rest at a position where the lower end 18C of the protective cover door 18 and the upper opening end 17E of the protective cover 17 come into contact. The proximity sensor A28 assembled to the protective cover 17 can detect that the distance from the magnet A29 assembled to the protective cover door 18 is less than a certain distance.

In FIG. 11, the protective cover door 18 is a sliding type that automatically opens the protective cover door 18 when inserting the print head into the cleaning tank 71, but the present invention is not limited to this. do not have. In other words, in order to facilitate cleaning of the structural parts inside the print head (nozzle 21, charging electrode 23, deflection electrode 24, gutter 25, etc.), any type of door can be used as long as it can be opened for cleaning. For example, the protective cover may have a door that can be opened and closed vertically or horizontally. Alternatively, the protective cover itself may be made openable and closable.

<Structure of head cleaning unit>
Next, the configuration of the head cleaning unit 4 of the inkjet recording apparatus 600 according to the first embodiment will be described using FIG. 12. FIG. 12 is a configuration diagram (a cross-sectional view of the cleaning nozzle 74) of the head cleaning unit 4 in the first embodiment.

In FIG. 12, the head cleaning unit 4 includes a cleaning tank 71 in which the print head 2 is accommodated during head cleaning, and a print head insertion installed above the cleaning tank 71 to set the print head 2 in the head cleaning unit 4. It is provided with a lid block 72 in which a part 72A is configured, and a recovery container 73 for storing recovery solvent 69B used in the head cleaning process.

The cover block 72 is provided to prevent foreign matter such as dust from entering the inside of the cleaning tank 71 from the print head insertion part 72A, which is an opening, when the print head 2 is not set in the print head insertion part 72A. A lid member 83 is assembled to the top. The lid member 83 is assembled to the lid block 72 via the lid hinge 82. This lid member 83 has a lid member protrusion 83A formed in order to reduce frictional resistance when the print head 2 is inserted into the head cleaning unit 4.

The lid block 72 includes a cleaning nozzle 74 for spouting head cleaning solvent 69A toward the print head 2, and a cleaning nozzle 74 for spraying air to dry the print head 2 wetted with the solvent 69A after head cleaning. An air nozzle 75 for this purpose is assembled by press-fitting.

The cleaning nozzle 74 includes a liquid flow path portion 74A formed inside the cleaning nozzle 74 so as to extend from the nozzle 21 toward the gutter 25 when the print head 2 is set in the head cleaning unit 4; A liquid discharge hole A section 74B is connected to the liquid discharge hole A section 74B for discharging the solvent 69A so as to aim at the nozzle 21, and a liquid discharging hole A section 74B is connected to the liquid flow path section 74A for discharging the solvent 69A so as to aim at the deflection electrode 24. A liquid ejection hole C part 74D is formed to eject the solvent 69A so as to be connected to the ejection hole B part 74C and the liquid flow path part 74A and to aim at the surface where the printing opening 17A of the protective cover 17 is formed. There is. A liquid flow path portion 74A formed in the cleaning nozzle 74 is connected to a liquid flow path portion 72B formed in the lid block 72.

The air nozzle 75 is connected to an air passage portion 75A formed inside the air nozzle 75 so as to extend from the nozzle 21 toward the gutter 25 when the print head 2 is set in the head cleaning unit 4. an air discharge hole A section 75B for discharging air so as to aim between the charged electrodes 23; and an air discharge hole connected to the air passage section 75A for discharging air so as to aim at the protective cover 17. A B section 75C is formed. Here, the air passage section 75A formed in the air nozzle 75 is connected to the air passage formed in the lid block 72.

The head cleaning unit 4 includes a cleaning tank 71 at the bottom of the lid block 72 for accommodating the print head 2 during head cleaning. The cleaning tank 71 has a side wall 71A formed to prevent the solvent 69A spouted from the cleaning nozzle 74 from scattering around, and a liquid flow for causing the solvent 69A discharged from the cleaning nozzle 74 to flow to the lower side of the cleaning tank 71. An exit portion 71D is formed. The cleaning tank 71 has a conical inner bottom part 71C formed in an inclined shape so that the liquid outlet part 71D is at the lowest position in order to make it easier for the solvent 69A to collect at the liquid outlet part 71D. There is. A temperature sensor B84 is installed inside the cleaning tank 71 to detect the ambient temperature of the head cleaning unit 4 and use it for various controls.

Further, the head cleaning unit 4 includes a recovery container 73 below the cleaning tank 71 for storing the solvent 69A used during head cleaning. The recovery container 73 stores the solvent 69A used during head cleaning, which drips from the liquid outlet 71D of the cleaning tank 71, as a recovery solvent 69B. The recovery container 73 has a liquid storage section 73A that holds the recovery solvent 69B, and the liquid storage section 73A is sealed by combining the upper part of the recovery container 73 and the lower part of the cleaning tank 71. The recovery container 73 also includes a liquid amount sensor 76 for detecting when the liquid level 69C of the recovered solvent 69B falls below a certain value and when the liquid level 69C rises above a certain value.

In the collection container 73, a filter (for the collection container) 77 is assembled at the lower part of the liquid storage section 73A in order to remove foreign matter mixed into the collection solvent 69B during head cleaning or the like. A liquid reservoir 73B is formed in the lower part of the filter (for recovery container) 77 to accommodate the filtered recovery solvent 69B. A solvent reuse channel 73C connected to the liquid reservoir 73B is formed in the recovery container 73, and the solvent reuse channel 73C is connected to the tube 823A via the reuse joint 80. This tube 823A forms part of the solvent reuse paths 823 to 824 and 807, and the recovered solvent 69B is supplied to the ink container 31 via the tube 823A.

In addition, the recovery container 73 is formed with a liquid discharge channel 73D connected to the liquid reservoir 73B, and the liquid discharge channel 73D is made of a fluorine-based solvent-resistant material via a discharge joint A81. It is connected to the manufactured tube 86. A discharge joint B87 is assembled to the tube 86 by press-fitting its end into the outlet portion on the opposite side to the discharge joint A81. A tube fixing part 71G is formed in the cleaning tank 71, and the discharge joint B87 is fixed to the tube fixing part 71G with a nut 89. A seal member 88 is assembled to the tube fixing portion 71G. The seal member 88 seals between the discharge joint B87 and the cleaning tank 71 so that the solvent 69A does not leak out of the cleaning tank 71 and the recovery container 73.

In addition, a communication hole 71F is formed in the center of the tube fixing part 71G of the cleaning tank 71, and when the discharge joint B87 is fixed to the cleaning tank 71, the space inside the cleaning tank 71 and the tube are connected to each other. The space inside 86 has the same pressure. Therefore, the space inside the recovery container 73, which communicates with the cleaning tank 71 through the liquid outlet 71D, and the space inside the tube 86 have the same pressure. Therefore, the liquid level 69C of the recovered solvent 69B and the liquid level 69D of the tube 86 are at the same liquid level. Thereby, even if the collection container 73 is opaque, for example, the amount of liquid in the collection container 73 can be confirmed by checking the liquid level in the tube 86.

Further, a liquid joint 78 connected to the liquid flow path portion 72B is assembled to the lid block 72, and a tube 822A is connected to the liquid joint 78 by a method such as press fitting. This tube 822A forms part of the head cleaning path 809 and 821 to 822, and is connected to the solvent container 33 via the tube 822A. Furthermore, an air joint 79 connected to the air passage section 72C is assembled to the lid block 72, and a tube 825A is connected to the air joint 79 by a method such as press fitting. This tube 825A forms part of a path 825 (for dry air) 825, and is connected to the pump (for dry air supply) 38 via the tube 825A.

The head cleaning unit 4 is covered with a cover 85 so that the tubes 822A, 823A, and 825A are not exposed to the outside of the head cleaning unit 4. The cover 85 covers the upper part of the lid block 72 and the collection container. It is fixed so as to sandwich the lower part of 73. The conduit (for the head cleaning unit) 6 is assembled at the bottom of the cover 85 so that it does not protrude outside and interfere with other production equipment.

Next, a configuration in which the print head 2 is set in the head cleaning unit 4 of the inkjet recording apparatus 600 according to the first embodiment will be described with reference to FIGS. 13 and 14. FIG. 13 is a partial cross-sectional view of the head cleaning unit 4, showing a state in which the print head 2 is set in the head cleaning unit 4 of the first embodiment. FIG. 14 is an enlarged view of the configuration of the print head 2, cleaning nozzle 74, and the vicinity thereof in FIG. 13.

12 to 14, the print head 2 is set in a head cleaning unit 4. In FIGS. The lid member 83 of the head cleaning unit 4 is opened by inserting the print head 2 into the print head insertion portion 72A. The print head 2 is in a state where the nozzle 21 , charging electrode 23 , deflection electrode 24 , and gutter 25 are pushed into the cleaning tank 71 . In order to prevent the head cleaning unit 4 from shifting in position with the print head 2, the inner wall surface of the hole in the print head insertion portion 72A and the outer wall surface of the print head 2 fit together, so that the head cleaning unit 4 does not easily shift from left to right or front to back. Furthermore, when the print head 2 is set in the head cleaning unit 4, the head base 16 of the print head 2 comes to rest at a position where it hits the print head support part 71B formed in the cleaning tank 71. The position of is stabilized.

A sensor mounting portion 71E is formed in the cleaning tank 71, and a proximity sensor B90 is assembled to the sensor mounting portion 71E. A magnet B30 is assembled to the head base 16 of the print head 2, and when the distance between the magnet B30 and the proximity sensor B90 approaches a certain distance or less, the proximity sensor B90 can detect it. When the print head 2 is set in the head cleaning unit 4, the magnet B30 and the proximity sensor B90 are close to each other within a certain distance, so the proximity sensor B90 is in a state of detection, and the print head 2 is It can be determined that it is set in the cleaning unit 4.

Further, when the print head 2 is set in the head cleaning unit 4, the opening/closing support portion 18A of the protective cover door 18 is arranged to abut against a door support portion 72D formed on the lid block 72. In the print head 2, since the weight of the print head 2 is greater than the spring force of the door closing spring 19, the door closing spring 19 is in a compressed state. The print head 2 moves downward until it hits the print head support part 71B, but the position of the protective cover door 18 is covered by the protective cover door 18 so that it does not move below the door support part 72D. The cleaning opening 17B is now in an open state. Then, the proximity sensor A28 assembled to the protective cover 17 detects that the distance from the magnet A29 assembled to the protective cover door 18 is less than a certain distance. It can be determined that the state is set to .

<How to use the head cleaning unit>
Next, the operation of the inkjet recording apparatus 600 according to the first embodiment when head cleaning processing is executed with the print head 2 set in the head cleaning unit 4 will be described using FIG. 15. . FIG. 15 is a cross-sectional view of the head cleaning unit 4 showing the flow of liquid inside the head cleaning unit 4 when the head cleaning process of Example 1 is being performed.

In FIG. 15, the inkjet recording apparatus 600 executes cleaning of the print head 2 by ejecting a solvent 69A from the cleaning nozzle 74 in the head cleaning process. The solvent 69A supplied to the cleaning nozzle 74 is directed in the direction of arrow EE (a direction in which the solvent 69A is spouted from the liquid discharge hole A portion 74B toward the nozzle 21) and arrow FF (the direction in which the solvent 69A is spouted from the liquid discharge hole B portion 74C toward the deflection electrode 24). The solvent 69A enters the inside of the protective cover 17 from the cleaning opening 17B and cleans the nozzles 21, deflection electrodes 24, etc. assembled on the print head 2. By spraying the solvent 69A onto the component parts, it is possible to clean stains caused by the ink 68A that adheres during operation or maintenance of the inkjet recording apparatus 600.

The solvent 69A sprayed onto components such as the nozzle 21 and the deflection electrode 24 assembled on the print head 2 drips and flows due to gravity in the direction shown by the arrow HH, and the print head 2 is set in the head cleaning unit 4. In this state, the charging electrode 23 and the gutter 25 located below the deflection electrode 24 can be cleaned with the solvent 69A. Further, the solvent 69A supplied to the cleaning nozzle 74 is directed in the direction shown by the arrow GG (direction in which the solvent 69A is spouted from the liquid discharge hole C portion 74D toward the surface where the printing opening 17A of the protective cover 17 is formed). The solvent 69A can be ejected to spray the protective cover 17 to clean the stains caused by the ink 68A attached to the outside of the print head 2.

In the head cleaning process, the solvent 69A used to clean the components such as the nozzle 21, the charging electrode 23, the deflection electrode 24, the gutter 25, and the protective cover 17 arranged on the print head 2 is applied to the arrows JJ and KK. The solvent drips down in the direction shown, flows into a collection container 73 installed at the bottom of the head cleaning unit 4, and is stored in the liquid storage section 73A as a collection solvent 69B.

Next, liquid level detection of the collection container 73 in each state of the inkjet recording apparatus 600 according to the first embodiment will be described using FIG. 16. FIG. 16 is a sectional view mainly showing the collection container 73 of the head cleaning unit 4 in this embodiment. In FIG. 16, (a) shows a state in which the liquid amount sensor 76 of the collection container 73 is not detecting either the maximum liquid amount detection section 76A or the minimum liquid amount detection section 76B. FIG. 16(b) shows a state in which the liquid amount sensor 76 is detecting the maximum liquid amount detection section 76A because the amount of recovered solvent 69B in the recovery container 73 has increased. FIG. 16(c) shows a state in which the liquid amount sensor 76 is detecting the minimum liquid amount detection section 76B because the amount of the recovered solvent 69B in the recovery container 73 is decreasing. .

In FIG. 16(a), the liquid level sensor 76 installed inside the recovery container 73 is connected to a float part 76C that moves up and down with the liquid level 69C of the recovery solvent 69B, and a liquid level sensor 76 that is lower than the liquid outlet part 71D of the cleaning tank 71. A maximum liquid amount detection section 76A is installed below and detects when the float section 76C approaches, and a maximum liquid amount detection section 76A is installed below the maximum liquid amount detection section 76A and above the filter (for collection container) 77 and detects when the float section 76C approaches. It is provided with a minimum liquid amount detection section 76B that detects when the section 76C approaches. The float portion 76C is in a state where neither the maximum liquid amount detecting portion 76A nor the minimum liquid amount detecting portion 76B is detecting. In this state, the recovery solvent 69B contained in the recovery container 73 can be normally replenished into the ink container 31. Further, the inkjet recording apparatus 600 can perform a head cleaning process by setting the print head 2 in the head cleaning unit 4 and ejecting the solvent 69A from the cleaning nozzle 74.

Next, in FIG. 11(b), a state will be described in which the liquid amount sensor 76 detects the maximum liquid amount detection section 76A because the amount of recovered solvent 69B in the recovery container 73 has increased. In the recovery container 73, by repeatedly performing the head cleaning process, the amount of recovery solvent 69B increases and the liquid level C becomes high. The liquid level sensor 76 can determine that the liquid level of the recovered solvent 69B is increasing because the float part 76C, which is displaced in conjunction with the liquid level 69C, and the maximum liquid level detection part 76A are approaching a certain distance or less. . When this state is detected, the inkjet recording apparatus 600 controls the cleaning nozzle 74 so as not to eject the solvent 69A in order to prevent the recovered solvent 69B from overflowing from the recovery container 73.

Next, in FIG. 11C, a state will be described in which the liquid amount sensor 76 detects the minimum liquid amount detection section 76B because the amount of recovered solvent 69B in the recovery container 73 is small. In the recovery container 73, since the head cleaning process has not been performed for a certain period of time, the amount of the recovery solvent 69B has decreased, and the liquid level 69C has become low. The liquid amount sensor 76 can determine that the amount of recovered solvent 69B is decreasing because the float portion 76C, which is displaced in conjunction with the liquid level, and the minimum liquid amount detection portion 76B are approaching a certain distance or less. When this state is detected, the inkjet recording apparatus 600 replenishes the ink container 31 with the solvent 69A from the solvent container 33 because the recovered solvent 69B stored in the recovery container 73 cannot be normally replenished into the ink container 31. , the solvent concentration of the ink 68A is controlled to be adjusted.

Next, a liquid draining operation of the collection container 73 of the inkjet recording apparatus 600 according to the first embodiment will be described using FIG. 17. FIG. 17 is a cross-sectional view of the head cleaning unit 4 when the collection container 73 is being drained. In the inkjet recording apparatus 600, when the amount of recovered solvent 69B in the recovery container 73 increases and the liquid amount sensor 76 detects the maximum liquid amount detection section 76A, the head cleaning process cannot be executed. In this case, when performing the head cleaning process, it is necessary to reduce the amount of the recovery solvent 69B in the recovery container 73 so that the maximum amount detection section 76A does not detect it. One method is to replenish the ink container 31 with the recovery solvent 69B in the recovery container 73, but it may take some time for the amount of recovery solvent 69B to decrease. Another method is to drain the recovery solvent 69B from the recovery container 73.

In FIG. 17, the discharge joint B87 is removed from the tube fixing part 71G of the cleaning tank 71, and the tube 86 is arranged so that the discharge joint B87 is below the collection container 73. Thereby, the recovery solvent 69B contained in the recovery container 73 can be discharged to the outside of the head cleaning unit 4.

<Effects of Example 1>
As described above, according to the first embodiment of the present invention, the print head can be easily cleaned by simply setting (inserting) the head cleaning unit, and furthermore, the solvent 69A used for head cleaning is collected in the collection container 73. can be accommodated. Further, the recovered solvent 69B can be reused to adjust the concentration of the ink 68A stored in the ink container 31. Therefore, according to the inkjet recording device 600, it is possible to reduce the effort of discarding the recovered solvent 69B during head cleaning work, and also to reduce the amount of recovered solvent 69B to be discarded, which makes it possible to reduce running costs for the customer. , an inkjet recording device 600 can be provided.

≪Example 2≫
An inkjet recording apparatus 700 in Example 2 of the present invention will be described using FIGS. 18 and 19. Note that the description of the parts that are common to the first embodiment described above will be omitted, and mainly the parts that are different from the first embodiment will be described.

<Exterior configuration>
FIG. 18 is an external perspective view showing an inkjet recording apparatus 700 in this embodiment, with a portion of the main body 1 being partially cut away so that the inside can be seen. FIG. 19 is a perspective view showing a state in which the print head 2 is attached to the cleaning tank 271 in the inkjet recording apparatus 700 in this embodiment.

First, as shown in FIG. 18A, an inkjet recording apparatus 700 includes a main body 201 and a print head 2 connected to the main body 1 by a conduit (for print head) 5. As shown in FIG. The main body 201 is equipped with a maintenance door 9 on the front. Inside the maintenance door 9, there is a container base 95 assembled at the bottom, an auxiliary ink container 32, a solvent container 33, and a container base 95 on the container base 95. Circulation system components such as a head cleaning unit 204 and a drive section 203 are assembled. A maintenance door handle 94 is attached to the upper center of the maintenance door 9 so that an operator can easily open and close the maintenance door 9. By opening the maintenance door 9, the inkjet recording apparatus 700 replenishes the auxiliary ink container 32 with ink 68A, the solvent container 33 with solvent 39A, and uses the head cleaning unit 204 to clean the print head 2. It can be cleaned with solvent 69A and can be used for daily maintenance work.

The inkjet recording apparatus 700 shown in FIG. 18(b) is in a state in which the maintenance door 9 is opened and the head cleaning unit 204 is pulled out. The maintenance door 9 can be opened up to an angle of 90°, and a rail 296 is formed on the back surface of the maintenance door 9. The head cleaning unit 204 can be pulled out on the rail 296 towards the front. The head cleaning unit 204 is configured integrally with the drive section 203 for the purpose of simplifying the components.

Next, with reference to FIG. 19, a state in which the print head 2 is set in the head cleaning unit 204 in the inkjet recording apparatus 700 will be described. The print head 2 is inserted into the print head insertion portion 72A of the head cleaning unit 204 from the tip of the print head 2. The inkjet recording apparatus 700 in this embodiment can clean the print head 2 by setting the print head 2 in the head cleaning unit 204 in this manner.

<Route configuration>
FIG. 20 is a diagram showing the overall path configuration of the inkjet recording apparatus 700 in this example. Note that descriptions of parts common to Example 1 will be omitted, and parts that are different from Example 1 will be mainly described.

The head cleaning paths 809, 821, and 841 of the inkjet recording apparatus 700 in this embodiment will be explained. In FIG. 20, the pump (for solvent) 37 is connected to a path 821 via a branch path 903, and the path 821 is connected to a connection part (head It is connected to the path 841 via a coupling (for head cleaning) 59A and a joint (for head cleaning) 260A. A solenoid valve (for nozzle cleaning) 55 for opening and closing the flow path is disposed in the path 841, and the solenoid valve (for nozzle cleaning) 55 is a filter for removing foreign matter mixed in the solvent 69A. (for head cleaning) 42.

A filter (for head cleaning) 42 is connected to a filter (for cleaning nozzle) 43 in order to remove foreign matter that may initially be mixed into the path 841. The filter (for cleaning nozzles) 43 is connected to a cleaning nozzle 74 provided inside the cleaning tank 71 of the head cleaning unit 204. Here, the space inside the cleaning tank 71 is configured to communicate with a recovery container 73 installed at the bottom.

Next, the solvent reuse paths 842, 824, and 807 of the inkjet recording apparatus 700 in this embodiment will be explained. In FIG. 20, the head cleaning unit 204 is equipped with a recovery container 73 that holds the recovery solvent 69B that has flowed in under its own weight after being used for head cleaning. A filter (for collection container) 77 is assembled to prevent the water from flowing into the path 842. The recovery container 73 is connected to a path 842 at the portion immersed in the recovery solvent 69B, and the path 842 is connected to the drive unit 203 inside the main body 201 to prevent fine foreign matter contained in the recovery solvent 69B from mixing with the ink 68A. A filter (solvent reuse) 44 is disposed for this purpose.

The filter (solvent reuse) 44 is connected to a solenoid valve (solvent reuse) 57 for opening and closing the flow path, and a path 842 in which the solenoid valve (solvent reuse) 57 is arranged is connected to the drive unit 203 It is connected to the path 824 via a connection part (solvent reuse) 59B and a joint (solvent reuse) 260B for relaying with. The path 824 is connected to the pump (for circulation) 36 arranged in the path 807 via the confluence path 902. As a result, the recovered solvent 69B held in the recovery container 73 can be replenished into the ink container 31, and can be reused for adjusting the ink concentration.

Next, the head drying air path 843 of the inkjet recording apparatus 700 in this embodiment will be explained. In FIG. 20, a drive unit 203 housed in a main body 201 is equipped with a pump (for supplying dry air) 38 used for suctioning and pumping air. forms an air suction port communicating with the inside of the main body 201. A pump (for supplying dry air) 38 is connected to an air nozzle 75 provided inside the cleaning tank 71 of the head cleaning unit 204 .

<Effects of Example 2>
As described above, according to the second embodiment of the present invention, the inkjet recording apparatus 700 has the head cleaning function and recovery function similar to the first embodiment, by arranging the cleaning tank 271 and the collection container 273 inside the main body 201. It is possible to provide an inkjet recording apparatus 700 that is equipped with a reuse function of the solvent 69B and has improved installation ease.

≪Other Examples≫
Although Examples 1 and 2 have been described above, the present invention is not limited to the above-described Example 1, and includes various modifications. Furthermore, the first and second embodiments described above are described in detail to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to having all the configurations described.

DESCRIPTION OF SYMBOLS 1... Main body, 2... Print head, 3... Drive unit, 4... Head cleaning unit, 5... Conduit, 6... Conduit, 8... Operation display section, 9... Maintenance door, 10... Control section, 11... Belt conveyor, 12A...Printing object (before printing), 12B...Printing object (after printing), 13...Print head fixing bracket, 14...conveyor column, 16...head base, 17...protective cover, 17A...printing opening, 17B ...Washing opening, 17C...Lower end of opening, 17D...Seat surface, 17E...Upper end of opening, 18...Protective cover door, 18A...Opening/closing support part, 18B...Elongated hole, 18C...Lower end of door, 18D...Upper end of door Part, 19...Door closing spring, 20...Pin, 21...Nozzle, 21A...Discharge port, 23...Charging electrode, 24...Deflection electrode, 25...Gutter, 25A...Gutter discharge port, 26...Switching valve, 27...Temperature sensor A, 28... Proximity sensor A, 29... Magnet A, 30... Magnet B, 31... Ink container, 31A... Liquid level sensor, 32... Auxiliary ink container, 33... Solvent container, 34... Pump (for supply), 35 ...Pump (for recovery), 36...Pump (for circulation), 37...Pump (for solvent), 38...Pump (for dry air supply), 39...Filter (for supply), 40...Filter (for recovery), 41 ...filter (for nozzle cleaning), 42...filter (for head cleaning), 43...filter (for cleaning nozzle), 44...filter (solvent reuse), 45...viscosity meter, 46...pressure regulating valve, 47...pressure sensor , 48...Charge sensor (detection means), 49...Solenoid valve (for supply), 50...Solenoid valve (for collection), 51...Solenoid valve (for circulation), 52...Solenoid valve (for viscosity measurement), 53...Solenoid Valve (for solvent replenishment), 54... Solenoid valve (for ink replenishment), 55... Solenoid valve (for nozzle cleaning), 56... Solenoid valve (for head cleaning), 57... Solenoid valve (solvent reuse), 58... Storage Area, 59A... Connection (for head cleaning), 59B... Connection (solvent reuse), 60A... Fitting (for head cleaning), 60B... Fitting (solvent reuse), 61A... Sealing plug (for solvent supply) , 61B...Sealing plug (solvent reuse), 63...Start button, 64...Stop button, 65...Display section, 68A...Ink, 68B...Ink particles, 69A...Solvent, 69B...Recovered solvent, 69C...Liquid level, 69D...Liquid level, 71...Cleaning tank, 71A...Side wall part, 71B...Print head support part, 71C...Conical inner bottom part, 71D...Liquid outlet part, 71E...Sensor mounting part, 71F...Communication hole part, 71G... Tube fixing part, 72...Lid block, 72A...Print head insertion part, 72B...Liquid flow path part, 72C...Air flow path part, 72D...Door support part, 73...Recovery container, 73A...Liquid storage part, 73B...Liquid Reservoir section, 73C...Solvent reuse channel, 73D...Liquid discharge channel, 74...Cleaning nozzle, 74A...Liquid channel section, 74B...Liquid discharge hole A part, 74C...Liquid discharge hole B part, 74D...Liquid discharge Hole C part, 75...Air nozzle, 75A...Air flow path part, 75B...Air discharge hole A part, 75C...Air discharge hole B part, 76...Liquid volume sensor, 76A...Maximum liquid volume detection part, 76B...Minimum liquid volume Detection part, 76C... Float part, 77... Filter (for collection container), 78... Liquid joint, 79... Air joint, 80... Reuse joint, 81... Discharge joint A, 82... Lid hinge, 83... Lid member, 83A ... Lid member protrusion, 84 ... Temperature sensor B, 85 ... Cover, 86 ... Tube, 87 ... Discharge joint B, 88 ... Seal member, 89 ... Nut, 90 ... Proximity sensor B, 91 ... Fixing jig (for main body) ), 92...Fixing jig (for conveyor), 93...Fixing jig fitting part, 94...Maintenance door handle, 201...Main body, 203...Drive unit, 204...Head cleaning unit, 260A...Joint (head cleaning) ), 260B...Joint (solvent reuse), 271...Cleaning tank, 273...Collection container, 295...Container base, 296...Rail, 600...Inkjet recording device, 700...Inkjet recording device, 801-803...Route (supply) ), 804...route (for recovery), 805...route (for exhaust), 806-807...route (for circulation), 808...route (for viscosity measurement), 809...route (for solvent supply), 810...route (for solvent replenishment), 811...path (for ink replenishment), 812...path (for nozzle cleaning), 821-822...path (for head cleaning), 823-824...path (solvent reuse), 825...path ( (for dry air), 841... path (for head cleaning), 842... path (solvent reuse), 843... path (for dry air), 901... merging path (for supply), 902... merging path (for circulation), 903... Branch route (for solvent)

Claims (14)

An inkjet recording device having a main body part and a print head part,
The main body includes an ink container that stores ink for printing on a printing target and supplies the ink to the print head, and a solvent container that stores a solvent and supplies the ink to the print head. ,
The print head unit includes a nozzle that is connected to the ink container and discharges ink supplied under pressure, a charging electrode that charges ink particles discharged from the nozzle, and ink particles that are charged by the charging electrode. It has a deflection electrode that deflects the ink, and a gutter that collects ink that is not used for printing.
Furthermore, a head mounting unit configured to be able to mount the print head section is provided,
The head mounting unit is an inkjet recording apparatus including a head detection section that detects whether or not the print head section is mounted using magnetic force. The inkjet recording device according to claim 1,
The head mounting unit is used when cleaning the print head using a solvent, and has a bottom portion formed with a communication hole through which a cleaning liquid passes, and a peripheral wall portion extending upward from the bottom portion. ,
An inkjet recording apparatus characterized in that the tip portion of the print head portion is surrounded by the peripheral wall portion when the print head portion is mounted. The inkjet recording device according to claim 1 or 2,
The inkjet recording apparatus is characterized in that the head mounting unit has a structure that is detachably attached to a side wall of the main body. The inkjet recording device according to any one of claims 1 to 3,
The head mounting unit is used for cleaning the print head section using a solvent when the print head section is mounted, and further includes a collection container for collecting a cleaning liquid used to wash the print head section. Features of inkjet recording device. The inkjet recording device according to claim 4,
An inkjet recording apparatus characterized in that the head cleaning unit performs periodic automatic head cleaning control. The inkjet recording device according to claim 4 or 5,
An ink jet recording apparatus characterized in that when the print head is attached to the head cleaning unit, ink is ejected to perform ink circulation. An inkjet recording device having a main body part and a print head part,
The main body includes an ink container containing ink for printing on a printing object and a solvent container containing a solvent,
The print head unit includes a nozzle that is connected to the ink container and discharges ink supplied under pressure, a charging electrode that charges ink particles discharged from the nozzle, and ink particles that are charged by the charging electrode. It has a deflection electrode that deflects the ink, and a gutter that collects ink that is not used for printing.
Furthermore, a head mounting unit configured to be able to mount the print head section is provided,
The head mounting unit is an inkjet recording apparatus including a collection container that collects the cleaning liquid used to clean the print head, and a liquid amount sensor that detects the amount of the cleaning liquid that has accumulated in the collection container. The inkjet recording device according to claim 7,
An inkjet recording apparatus characterized in that the head cleaning unit includes head detection means for detecting whether or not the print head is attached. The inkjet recording device according to claim 8,
An inkjet recording apparatus, wherein the head detection means detects attachment of the print head using magnetic force. The inkjet recording device according to any one of claims 7 to 9,
An inkjet recording apparatus characterized in that the head cleaning unit performs periodic automatic head cleaning control. The inkjet recording device according to any one of claims 7 to 10,
An ink jet recording apparatus characterized in that when the print head is attached to the head cleaning unit, ink is ejected to perform ink circulation. The inkjet recording device according to claim 10 or 11,
An inkjet recording apparatus characterized in that, by the overflow detection, control is performed to stop ink ejection or head cleaning when the amount of ink or cleaning liquid in the collection container exceeds a certain value. The inkjet recording device according to any one of claims 7 to 12,
The head mounting unit has a bottom portion formed with a communication hole through which cleaning liquid passes, and a peripheral wall portion extending upward from the bottom portion,
An inkjet recording apparatus characterized in that the tip portion of the print head portion is surrounded by the peripheral wall portion when the print head portion is mounted. The inkjet recording device according to any one of claims 7 to 13,
An inkjet recording apparatus characterized in that a control is performed to suction a solvent gas during cleaning of the print head section from at least one of the gutter and a nozzle of the print head section.